IFNG and parasitic infectious disease: It has been reported in Phase 2a challenge trials of RTS,S/AS02A [32], [40], RTS,S/AS01B (personal communication, K. Kester) and heterologous prime-boost immunization regimens with antigen based on thrombospondin-related adhesion protein (TRAP) [41], [42] that elevated antigen-specific IFN-γ responses are associated with a delay in the prepatent period and protection against parasitemia.